But there's plenty of variety to be found farther down the list, with relatively recent concepts such as Lego-building classes (No. 5), high-school sports marketing (No. 46) and fitness for seniors (No. 58). What they have in common is their youth: All the companies on the list began franchising in the last five years.

Along with that requirement, the 75 companies on the following pages were ranked according to Entrepreneur's objective, quantifiable criteria, including financial strength and stability, growth rate and system size. Other factors considered in the ranking include startup costs, litigation, percentage of terminations and whether the company provides financing.

The list is not intended as an endorsement of any particular franchise. Always do your research before investing in any franchise, new or longstanding. Read the company's legal documents, consult with attorneys and accountants and talk to existing franchisees about their experiences.